Weeping balloon devices

ABSTRACT

Catheters with weeping balloons can be used for various medical purposes. For example, in some embodiments provided herein weeping balloons are used for catheter visualization devices. In some embodiments, weeping balloons are used to deliver therapeutic agents. Weeping balloons can include openings of a selected size and shape through which a fluid gradually flows or “weeps.” The design of the openings can affect performance characteristics such as, but not limited to, fluid flow rate, tear resistance, and mitigation of counter-flow.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/491,651, filed Apr. 19, 2017, now U.S. Pat. No. 10,512,759, whichclaims the benefit of priority under 35 U.S.C. § 119(e) to U.S.Provisional Application No. 62/324,424, filed Apr. 19, 2016, the entiredisclosure of which are herein incorporated by reference.

TECHNICAL FIELD

This disclosure relates to medical devices such as catheter-basedweeping balloon devices. In one example implementation this disclosurerelates to weeping balloon catheter visualization devices. Thisdisclosure also relates to various hole designs of the weeping balloons.

BACKGROUND

The presence and movement of opaque bodily fluids such as bloodgenerally make in vivo imaging of tissue regions within a patientdifficult. Medical devices may therefore, in some cases, be used tovisualize interior regions of a patient's body by depicting a visualconstruct. For example, ultrasound devices may be used to produce invivo ultrasound images from within a body. In another example, mappingdevices having position sensors for generating a map depicting a two- orthree-dimensional image of a patient's interior region may also be used.Visual information provided by such devices can often be limitedbecause, for example, the mapping device may not be able to providevisual information of the tissue surface condition within a heartchamber. Thus, there is a need for medical devices that can provideimproved visualization for viewing a blood-filled cavity or vesselwithin the patient.

Medical devices may, in some cases, use an inflatable imaging balloon toobtain in vivo imaging of the patient's tissue regions. The imagingballoon can be introduced into the patient's body in a deflated state.Once introduced, the imaging balloon can be inflated and pressed againsta targeted tissue region for imaging. Imaging can be achieved by use ofan optical fiber or other electronic apparatus for viewing tissuethrough the wall of the inflated balloon.

Imaging balloons may encounter issues that affect the quality of theimage being captured. For example, because of intervening blood betweenthe balloon and tissue, imaging balloons may produce poor or blurredtissue images if the balloon is not firmly pressed against the tissuesurface.

SUMMARY

This disclosure provides medical devices such as catheters with weepingballoons. For example, this disclosure provides weeping balloon cathetervisualization devices and hole designs of the weeping balloons. Theballoon catheter visualization devices, systems and methods providedherein include features that improve minimally invasive surgicaltechniques used during procedures such as, but not limited to, heartvalve repair procedures. While some of the devices, systems and methodsprovided herein are described in the context of a tricuspid valverepair, other types of minimally invasive surgical procedures are alsoenvisioned within the scope of this disclosure. For example, the systemsand methods provided herein may also be advantageously applied to tissuerepair procedures in the other areas of the heart, peripheralvasculature and other locations within the body.

In some aspects, a weeping balloon device includes a catheter shaftdefining a lumen and an inflatable balloon attached to the cathetershaft. The balloon includes a balloon wall that defines an interiorspace in fluid communication with the lumen. The balloon wall alsodefines a plurality of openings in fluid communication with the interiorspace. The weeping balloon device also includes, at each opening of theplurality of openings, at least one additional layer of materialattached to the balloon wall to reinforce the structure around openings.

Such a weeping balloon device may optionally include one or more of thefollowing features. Each additional layer of material may define anadditional opening that is concentric with an opening of the pluralityof openings defined by the balloon wall. In some embodiments, at leastone of the additional layers of material does not define any openings.In various embodiments, an open region between the at least oneadditional layer of material and the balloon wall provides a passagewayin fluid communication with the opening through the balloon wall that isat the at least one additional layer of material. At least one of theadditional layers of material may define a plurality of additionalopenings that are in fluid communication with the opening through theballoon wall that is at the at least one additional layer of material.In some embodiments, the plurality of additional openings are smallerthan the opening through the balloon wall that is at the at least oneadditional layer of material. In particular embodiments, none of theplurality of additional openings are coincident with the opening throughthe balloon wall that is at the at least one additional layer ofmaterial. At least one opening of the plurality of openings may be aslit. In some embodiments, at least one end of the slit is formed toinclude a stress concentration relief shape.

In some aspects, a weeping balloon device includes a catheter shaftdefining a lumen and an inflatable balloon attached to the cathetershaft. The balloon includes a balloon wall defining an interior space influid communication with the lumen. The balloon wall also defines aplurality of openings in fluid communication with the interior space.The weeping balloon device also includes a plurality of ribs projectingfrom a surface of the balloon wall. A respective rib of the plurality ofribs is located at each opening of the plurality of openings, and arespective opening of the plurality of openings extends through therespective rib.

Such a weeping balloon device may optionally include one or more of thefollowing features. At least one opening of the plurality of openingsmay be a slit. In some embodiments, the slit does not extend radially inrelation to the balloon. The plurality of ribs may project from anexterior surface of the balloon wall. In some embodiments, the pluralityof ribs are integrally formed with the balloon wall.

In some aspects, a weeping balloon device includes a catheter shaftdefining a lumen and an inflatable balloon attached to the cathetershaft. The balloon includes a balloon wall defining an interior space influid communication with the lumen. The balloon wall also defines aplurality of openings in fluid communication with the interior space.The plurality of openings are defined in areas of the balloon wall that,while the balloon is not fully inflated, are depressed radially inwardin comparison to other areas of the balloon wall. While the balloon isnot fully inflated, the plurality of openings are sealed, and while theballoon is fully inflated, the plurality of openings are open.

Such a weeping balloon device may optionally include one or more of thefollowing features. While the balloon is fully deflated, the balloonwall may define folds and the plurality of openings can be located incrotches between adjacent folds. In some embodiments, in the foldsextend radially along generally linear paths. In some embodiments, thefolds extend radially along curved paths. While the balloon is partiallyinflated, the balloon wall may define localized depressions, and theopenings may be located in the localized depressions. In someembodiments, while the balloon is fully inflated, the localizeddepressions are eliminated.

The details of one or more embodiments of balloon catheter visualizationdevices, systems, and methods provided herein are set forth in theaccompanying drawings and the description below. Other features,objects, and advantages will be apparent from the description anddrawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is an illustration of an exemplary balloon catheter visualizationdevice within a human anatomy.

FIG. 2 is a perspective view of a distal end portion of an exemplaryballoon catheter visualization device.

FIG. 3 is a plan view of a portion of a weeping balloon device inaccordance with some embodiments.

FIG. 4 is a cross-sectional view of the portion of the weeping balloondevice of FIG. 3.

FIG. 5 is a cross-sectional view of a portion of another weeping balloondevice in accordance with some embodiments.

FIG. 6 is a cross-sectional view of a portion of another weeping balloondevice in accordance with some embodiments.

FIG. 7 is a plan view of a portion of another weeping balloon device inaccordance with some embodiments.

FIG. 8 is a plan view of a portion of another weeping balloon device inaccordance with some embodiments.

FIG. 9 is a plan view of a portion of another weeping balloon device inaccordance with some embodiments.

FIG. 10 is a plan view of a portion of another weeping balloon device inaccordance with some embodiments.

FIG. 11 is a plan view of the portion of the weeping balloon device ofFIG. 10 with the opening in an expanded configuration.

FIG. 12 is a distal end view of another weeping balloon device inaccordance with some embodiments.

FIG. 13 is a cross-sectional view of a portion of the weeping balloondevice of FIG. 12.

FIG. 14 is an end view of another weeping balloon device in accordancewith some embodiments. The balloon is shown in an uninflatedconfiguration.

FIG. 15 is a side view of the weeping balloon device of FIG. 14.

FIG. 16 is an end view of another weeping balloon device in accordancewith some embodiments. The balloon is shown in an uninflatedconfiguration.

FIG. 17 is a side view of the weeping balloon device of FIG. 14.

FIG. 18 is a cross-sectional view of a portion of the weeping balloondevices of FIGS. 14-17. The cross-sectional view is shown with theballoon in an uninflated configuration.

FIG. 19 is a cross-sectional view of a portion of the weeping balloondevices of FIGS. 14-17. The cross-sectional view is shown with theballoon in an inflated configuration.

FIG. 20 is a distal end view of another weeping balloon device inaccordance with some embodiments.

FIG. 21 is a cross-sectional view of a portion of the weeping balloondevice of FIG. 20. The cross-sectional view is shown with the balloon inan uninflated configuration.

FIG. 22 is a cross-sectional view of a portion of the weeping balloondevices of FIG. 20. The cross-sectional view is shown with the balloonin an inflated configuration.

DETAILED DESCRIPTION

Catheters with weeping balloons can be used for various medicalpurposes. For example, in some embodiments weeping balloons are used forcatheter visualization devices. In some embodiments, weeping balloonsare used to deliver therapeutic agents. Weeping balloons can includeopenings of a selected size and shape through which a fluid graduallyflows or “weeps.” As described further below, the design of the openingscan affect performance characteristics such as, but not limited to,fluid flow rate, tear resistance, and mitigation of counter-flow.

Balloon catheter visualization device, systems, and methods providedherein can allow for balloon catheter visualization of a targetlocation, which can provide anatomy and pathology identification as wellas device placement visual feedback to the physician user during aminimally invasive method. Balloon catheter visualization devices,systems, and methods provided herein can include an elongate, compliantballoon having a transparent wall. In some cases, the transparent wallcan include portions arranged to be sutured to an anatomical locationthrough the transparent wall and to separate from the remainder of theballoon catheter. In some case, the balloon can include pores to allowfor the balloon to “weep” to provide a visually clear area surroundingthe balloon. In some cases, the balloon wall (e.g., a transparentballoon wall) can have a structure that limits the propagation of tears.In some cases, the balloon can include polymeric fibers within theballoon material.

Referring to FIG. 1, an exemplary balloon catheter visualization system100 can be used to visualize tissue structures within a human anatomy.In some cases, balloon catheter visualization system 100 can be insertedinto a right atrium of a heart 10 through a brachial vein or a jugularvein. Balloon catheter visualization system 100 includes a tubular body112 (which can also be described as an elongate shaft or catheter)having a proximal end portion 114 with a proximal end 116 and a distalend portion 118 with a distal end 120. In some embodiments, proximal endportion 114 can couple to a catheter hub 122 or a manifold. In thedepicted embodiment, the distal end portion 118 includes an integratedcamera (not shown), a fastening tool 124 with a fastener and at leastone balloon 108 (also described as balloon member).

In some embodiments, the integrated camera and fastening tool 124 can bedisposed within balloon 108. As shown in FIG. 1, balloon 108 can form adistal tip of balloon catheter visualization system 100. In someembodiments, balloon 108 is a weeping balloon. That is, balloon 108 canbe configured to slowly transmit fluid through a wall of balloon 108, asdescribed herein. Such fluid can be visually clear or transparent andcan displace blood that would otherwise obscure visualization of areasadjacent to the balloon 108. In some embodiments, as described furtherbelow, the portions of the balloon 108 that are configured to slowlytransmit fluid can be advantageously designed to resist expansion whileunder pressure, resist tearing, and to resist blood reflux, for example.Accordingly, the weeping balloon design embodiments provided hereinprovide improved performance in comparison to prior conventional weepingballoon devices.

In some embodiments, the fastening tool 124 can pass a fastener throughthe balloon 108 to suture an anatomical location outside the balloon.The balloon 108 can be filled with an inflation medium, such as salinesolution, that can be safely delivered to the patient, thus leakage fromresulting openings in the balloon 108 caused by the passing of thefastener through the balloon 108 can be tolerated.

In some embodiments, balloon catheter visualization system 100 includesat least one tubular body 112 defining a lumen (not shown). In somecases, balloon catheter visualization system 100 can include multipletubular bodies, in which each tubular body defines at least one lumen.Each tubular body 112 can optionally include multiple lumens, forexample, coaxial or non-coaxial lumens. Balloon catheter visualizationsystem 100 can have one or more lumens that extend partially or fullythorough one or more tubular bodies 112. One or more lumens can be usedas a conduit adapted to receive components, e.g., integrated camera orfastener tools, and/or inflation media, e.g., saline. In some cases, oneor more lumens can be adapted to jet inflation media, e.g., saline, intodistal end portion 118 of balloon catheter visualization device 100.

In some embodiments, catheter hub 122 generally connects an externalfluid supply to one or more lumens of balloon catheter visualizationsystem 100. Catheter hub 122 can include one or more ports 128 tofacilitate a fluid connection to another medical device or a fluidsource. For example, port 128 can supply saline solution into one ormore lumens of tubular body 112. Catheter hub 122 may be coupled totubular body 112 directly or indirectly. In some cases, a flexibletubing, sometimes referred to as a strain relief tubing, is coupledbetween manifold 122 and the tubular body 112 at the proximal end 116 toprovide a longitudinal tapered transition between catheter hub 122 andtubular body 112. Flexible tubing can help to increase kink resistanceof tubular body 112 at proximal end portion 114.

Referring to FIG. 2, a distal end of exemplary balloon cathetervisualization system 100 can include the balloon 108. In someembodiments, the exterior surface of balloon 108 (which can be primarilysilicone, for example) may have a hydrophilic coating to further enhancenavigation, lubricity, surface wetting, and visual quality. Such acoating may also reduce traumatic abrasion to anatomy and tissues. Suchcoatings may be dipped, sprayed, or deposited on the exterior surface ofballoon 108. In some embodiments, the exterior surface of balloon 108may include a matrix lamination such as electrospun hydrophilicmaterials. In particular embodiments, the inner surface of balloon 108may have a hydrophilic coating that may also enhance visualquality/clarity.

In some embodiments, the balloon 108 includes tear lines 196, orweakened sections, in the balloon wall 164 that define pledgets 126. Insome embodiments, pledgets 126 are adapted to be sutured to anatomicallocations and separated from balloon 108. The balloon cathetervisualization system 100 can include an elongate, tubular body 112 witha distal end portion 154. A distal end 156 of distal end portion 154 canbe either directly or indirectly coupled to a balloon 108. For example,tubular body 112 can be coupled to balloon 108 indirectly by using anintermediate catheter shaft 157. The intermediate catheter shaft 157 cancouple to a proximal end 162 of balloon 108 and a catheter interfaceportion 158 of tubular body 112.

In some embodiments, balloon 108 is disposed at or near to distal end156 of tubular body 112. Balloon 108 can include the proximal end 162, adistal end 163 and a wall 164 that extends from an interior surface 165to an exterior surface 166. In the depicted embodiment, balloon 108forms a distal tip 170 of balloon catheter visualization system 100. Asdescribed further herein, balloon 108 can be filled with an inflationmedia in an interior cavity 168 defined between proximal and distal ends162, 163. Balloon 108 can be a weeping balloon device, i.e., a balloonstructure that defines one or more openings or perforations 172extending through wall 164. Balloon 108 can have a distal face thatdefines openings 172 of the weeping balloon 108. In such a case, thedistal face of the balloon 108 can be abutted to tissue and the tissuecan be visualized using the balloon catheter visualization system 100.

Still referring to FIG. 2, in some embodiments distal end of tubularbody 112 can include a plurality of lumens 174. Each lumen of pluralityof lumens 174 can longitudinally extend within tubular body 112(entirely or partially therethrough). Each lumen 174 can be formed fromone of various cross-sectional shapes, e.g., circle, oval, slot, square,rectangular, triangular, trapezoid, rhomboid, or irregular shape. Theshape of the lumen may facilitate receiving other components of ballooncatheter visualization system 100. For example, one or more lumens 174can be used to receive a fastening tool (not shown), a camera 176, fiberoptic light cables (not shown), electrical cables (not shown), inflationmedia, and combinations thereof. In some embodiments, tubular body 112defines a central lumen 178 for receiving a fastening tool (not shown)for delivering a fastener (not shown), two or more lumens for receivingfiber optic light cables 180, one or more lumens for deliveringinflation media 182, and one or more lumens for receiving camera 176.

In some embodiments, balloon 108 of balloon catheter visualizationsystem 100 is a weeping balloon. A weeping balloon 108, in the contextof the present disclosure, includes a balloon structure defining one ormore perforations 172 (also described as apertures, hole, slits,openings, pores, micropores, etc., extending through a balloon wall). Assuch, weeping balloons 108 can transfer fluid through the balloon wall164, from the interior cavity 168 to the exterior surface 166 of balloon108. Transferring fluid (e.g., inflation media) to exterior surface 166can provide a benefit of displacing blood from exterior surface 166 ofballoon 108 that would otherwise blur or obstruct visual imaging throughballoon 108. In other words, inflation media transferred through the oneor more openings 172 can help keep the exterior surface 166 of balloon108 visually clear. When a plain balloon is placed against an anatomicalsurface, blood can be trapped on the balloon surface and thus obscurethe view, but inflation media (e.g., saline) exiting the openings 172 ofa weeping balloon 108 can wash away this blood on the balloon surfaceadjacent to the anatomical surface.

In some embodiments, a weeping balloon 108 used in a balloon cathetervisualization system 100 or other medical device has at least 3 openings172. In some embodiments, weeping balloons 108 used in balloon cathetervisualization systems 100 or other medical devices can have between 3and 10,000 openings, between 3 and 1,000 openings, between 3 and 100openings, or between 3 and 10 openings, or between 4 and 10 openings, orbetween 5 and 10 openings, or between 6 and 10 openings, or between 7and 10 openings, or between 8 and 10 openings, 9 openings, 10 openings,or between 10 and 12 openings, or between 10 and 15 openings, or between10 and 20 openings, or more than 20 openings are included in the weepingballoons provided herein.

In some cases, particularly in cases where the number of openings iswithin the above ranges, the number and dimensions of openings in aweeping balloon 108 used in a balloon catheter visualization system 100or other medical device allows for a fluid flow rate of between about 1and about 50 ml/minute. In some cases, the number and dimensions ofopenings in a weeping balloon 108 described herein provide a fluid flowrate between about 3 ml/minute and about 10 ml/minute. In some cases, aweeping balloon 108 used in balloon catheter visualization systems 100and other medical devices can have a plurality of openings that perfusefluid (e.g., an inflation media such as saline) through the balloon andinto the blood. In some cases, a weeping balloon 108 used in a ballooncatheter visualization system 100 or device provided herein can have agreater opening density in portions of the balloon wall 164 in thecenter of the field of view and a lower opening density around aperiphery of the field of view.

While a visualization system 100 is used to describe the weepingballoons 108 provided herein, it should be understood that thevisualization system 100 is just one example implementation. The weepingballoon devices provided herein can be used in various otherimplementations. For example, in some embodiments the weeping balloondevices provided herein can be used to deliver a therapeutic agent.

Referring to FIGS. 3 and 4, a weeping balloon 200 can define an opening210 through which fluid can pass. While a single opening 210 is depictedin this portion of weeping balloon 200, it should be understood that, asdescribed above, any number of such openings 210 can be included in theweeping balloon 200.

Weeping balloon 200 is designed with features that are directed tokeeping the size of opening 210 substantially consistent even withfluctuations in the fluid pressure internal to the balloon 200. Inparticular, weeping balloon 200 includes a layer of reinforcementmaterial 230 that is laminated on the balloon wall 220 around theopening 210. Both the balloon wall 220 and the reinforcement material230 define the opening 210.

The reinforcement material 230 supplements the stiffness of balloon wall220 around opening 210 to provide greater resistance to the deformationof opening 210 that might otherwise occur without the presence of thereinforcement material 230. For example, as the fluid pressure withinthe internal space defined by the weeping balloon 200 increases, theballoon wall 220 will tend to stretch. The stretching of the balloonwall 220 will tend to enlarge the opening 210. Such enlarging of theopening 210 may be undesirable in some cases. For example, as theopening 210 enlarges, the opening 210 may become too large and, inresult, too much fluid may be transmitted through opening 210.

To resist the enlarging of opening 210, the material stiffness aroundopening 210 can be increased by adding the reinforcement material 230.At other areas of the balloon 200, the single layer balloon wall 220(without the reinforcement material 230) can provide a higher complianceto allow for a desired low-profile collapsibility of balloon 200, forexample.

In some embodiments, the reinforcement material 230 is a differentmaterial than the balloon wall 220. For example, in some embodiments thereinforcement material 230 is made of polyether block amide (e.g.,PEBAX®) while the balloon wall 220 is made of silicone (e.g., about 30 Adurometer). It should be understood that other combinations of materialsare also envisioned. In another non-limiting example, the balloon wall220 is made of silicone at a first durometer (e.g., about 30 Adurometer) and the reinforcement material 230 is made of silicone at asecond durometer (e.g., about 50 A durometer).

The reinforcement material 230 is attached to the balloon wall 220. Insome cases, an adhesive is used to bond the reinforcement material 230to the balloon wall 220. For example, in some cases a UV curablesilicone adhesive is used to bond the reinforcement material 230 to theballoon wall 220. Other types of adhesives can also be used. In somecases, the reinforcement material 230 is molded onto the balloon wall220.

While in the depicted embodiment the reinforcement material 230 is acircular shape, in some embodiments the reinforcement material 230 has adifferent shape. For example, in some embodiments the reinforcementmaterial 230 is ovular, elliptical, rectangular, triangular, polygonal,e.g., and the like. Further, the thickness of the reinforcement material230 can be constant or variable. For example, the outer edges of thereinforcement material 230 can have a tapered shape away from theopening 210.

As described above, both the reinforcement material 230 and the balloonwall 220 define the opening 210. In the depicted embodiment, the opening210 is the same size in each of the reinforcement material 230 and theballoon wall 220. In some embodiments, the opening defined by thereinforcement material 230 is larger than the opening defined by theballoon wall 220. In some embodiments, the opening defined by thereinforcement material 230 is smaller than the opening defined by theballoon wall 220. For example, in some embodiments the diameters of theopenings defined by the reinforcement material 230 and the balloon wall220 differ by about 5% to about 15%, or about 10% to about 20%, or about15% to about 25%, or about 20% to about 30%, or about 25% to about 35%,or about 30% to about 40%, or more than about 40%.

While in the depicted embodiment the opening 210 is circular, in someembodiments the opening 210 has a different shape. For example, in someembodiments the opening 210 is a slot, a slit, ovular, elliptical,rectangular, triangular, and the like. In some embodiments, differentshapes may be used for the openings 210 at different locations on theweeping balloon 200.

Referring to FIG. 5, another example weeping balloon 300 can beconfigured to resist deformation of an opening 310 through which fluidcan pass. While a single opening 310 is depicted in this portion ofweeping balloon 300, it should be understood that, as described above,any number of such openings 310 can be included in the weeping balloon300.

The laminated construction of weeping balloon 300 includes a firstballoon wall layer 320, a reinforcement material 330, and a secondballoon wall layer 340. The reinforcement material 330 is sandwichedbetween the first balloon wall layer 320 and the second balloon walllayer 340. In some embodiments, the second balloon wall layer 340extends all around the balloon 300 (thereby serving as a contiguousouter surface of the entire balloon 300). In some embodiments, thesecond balloon wall layer 340 is a localized layer that does not extendall around the balloon 300.

Various materials can be used for the first balloon wall layer 320,reinforcement material 330, and second balloon wall layer 340. In onenon-limiting example, the first balloon wall layer 320 is silicone, thereinforcement material 330 is PEBAX®, and the second balloon wall layer340 is silicone. Other materials are also envisioned.

In some embodiments, the first balloon wall layer 320 can be formed bydip-molding, then the reinforcement material 330 can be bonded to thefirst balloon wall layer 320. After that, a second dip-molding can formthe second balloon wall layer 340 on top of the first balloon wall layer320 and the reinforcement material 330. Alternatively, the secondballoon wall layer 340 can be bonded onto the first balloon wall layer320 and the reinforcement material 330.

The opening 310 can include any of the variations (e.g., shapes, sizes,etc.) described above in reference to the opening 210. For example, inthe depicted embodiment the opening 310 defined by the first balloonwall layer 320 is larger than the opening 310 defined by thereinforcement material 330 and the second balloon wall layer 340. Inaddition, the opening 310 defined by the second balloon wall layer 340is smaller than the opening 310 defined by the reinforcement material330 and the first balloon wall layer 320. In some embodiments, theopening 310 defined by the reinforcement material 330 is larger than theopenings 310 defined by the first and second balloon wall layers 320 and340. Any such combinations of differing or equivalent sizes of opening310 (in the various layers) can be utilized and are within the scope ofthis disclosure.

Referring to FIG. 6, another example weeping balloon 400 can beconfigured to resist deformation of an opening 410 through which fluidcan pass. While a single opening 410 is depicted in this portion ofweeping balloon 400, it should be understood that, as described above,any number of such openings 410 can be included in the weeping balloon400.

In this example, the multi-layer construction (i.e., first balloon walllayer 420, reinforcement material 430, and second balloon wall layer440) around opening 410 is similar to that of weeping balloon 300 exceptthat the second balloon wall layer 440 is configured differently. Inparticular, in the depicted embodiment the second balloon wall layer 440includes a thicker area surrounding the opening 410 and the opening 410defined by the second balloon wall layer 440 is conical or tapered(e.g., a tapered slit). Such a design may help seal opening 410 tothereby resist inflow of blood into the interior of the weeping balloon400.

Example weeping balloon 400 illustrates that the thickness of the layers420, 430, and/or 440 need not be uniform. For example, in the depictedembodiment the second balloon wall layer 440 includes a thicker areasurrounding the opening 410. Such a variation in thickness can beincorporated into any of the layers 420, 430, and/or 440 of the weepingballoon 400 and into any of the other weeping balloon embodimentsprovided herein.

Referring to FIG. 7, another example weeping balloon 500 can beconfigured to control the passage of fluid through an opening 510. Whilea single opening 510 is depicted in this portion of weeping balloon 500,it should be understood that, as described above, any number of suchopenings 510 can be included in the weeping balloon 500.

In the depicted embodiment, the opening 510 (a slit in this example, butthe opening 510 could be a hole of various shapes, etc.) is defined bythe balloon wall 520. An overlaid material 530 is attached to theballoon wall 520 such that the overlaid material 530 at least partiallycovers the opening 510. In the depicted embodiment, the overlaidmaterial 530 fully covers the opening 510.

In some embodiments, the overlaid material 530 is bonded to the balloonwall 520. For example, in the depicted embodiment the overlaid material530 is bonded to the balloon wall 520 at a first bonded region 532 a anda second bonded region 532 b. The bonded regions 532 a and 532 b do notfully surround the opening 510. Instead, at least one open region 534 aand/or 534 b exists through which fluid can flow. In the depictedembodiment, two open regions 534 a and 534 b are included. In someembodiments, three, four, or more than four open regions are included.The open regions 534 a and 534 b allow fluid flowing from opening 510 toflow out onto the balloon wall 520 adjacent to the open regions 534 aand 534 b. Hence, balloon 500 is a weeping balloon.

The configuration of example weeping balloon 500 can provide a number offunctional advantages. First, the overlaid material 530 can stiffen theweeping balloon 500 in the area around the opening 510. Hence, theoverlaid material 530 can provide resistance to an enlarging of theopening 510 that may otherwise occur in response to pressurization ofthe balloon 500. Second, the overlaid material 530 can serve as aone-way valve. That is, while the overlaid material 530 allows fluidflowing from the opening 510 to pass through onto the balloon wall 520adjacent to the open regions 534 a and 534 b, the overlaid material 530will tend to resist fluid flow in the reverse direction. For example, ifthe pressure exterior to the balloon 500 is greater than the pressureinterior to the balloon 500, the overlaid material 530 will be pressedagainst the balloon wall 520, thereby advantageously sealing the opening510.

Referring to FIG. 8, another example weeping balloon 600 can beconfigured to control the passage of fluid through an opening 610. Whilea single opening 610 is depicted in this portion of weeping balloon 600,it should be understood that, as described above, any number of suchopenings 610 can be included in the weeping balloon 600.

In the depicted embodiment, the opening 610 (a slit in this example, butthe opening 610 could be a hole of various shapes, etc.) is defined bythe balloon wall 620. An overlaid material 630 is attached to theballoon wall 620 such that the overlaid material 630 at least partiallycovers the opening 610. In the depicted embodiment, the overlaidmaterial 630 fully covers the opening 610.

In some embodiments, the overlaid material 630 is bonded to the balloonwall 620. For example, in the depicted embodiment the overlaid material630 is bonded to the balloon wall 620 at a bonded region 632. The bondedregion 632 does not fully surround the opening 610. Instead, at leastone open region 634 (at a free end of the overlaid material 630) existsthrough which fluid can flow. In some embodiments, two, three, four, ormore than four open regions are included. The open region 634 allowsfluid flowing from opening 610 to flow out onto the balloon wall 620adjacent to the open region 634. Hence, balloon 600 is a weepingballoon.

The overlaid material 630 can serve as a one-way valve. That is, whilethe overlaid material 630 allows fluid flowing from the opening 610 topass through onto the balloon wall 620 adjacent to the open region 634,the overlaid material 630 will tend to resist fluid flow in the reversedirection. For example, if the pressure exterior to the balloon 600 isgreater than the pressure interior to the balloon 600, the overlaidmaterial 630 will be pressed against the balloon wall 620, therebyadvantageously sealing the opening 610.

Referring to FIG. 9, another example weeping balloon 700 can beconfigured to control the passage of fluid through an opening 710. Whilea single opening 710 is depicted in this portion of weeping balloon 700,it should be understood that, as described above, any number of suchopenings 710 can be included in the weeping balloon 700.

In the depicted embodiment, the opening 710 (a circular hole in thisexample, but the opening 710 could be a slit or a hole of variousshapes, etc.) is defined by the balloon wall 720. An overlaid material730 is attached to the balloon wall 720 such that the overlaid material730 covers the opening 710.

In some embodiments, the overlaid material 730 is bonded to the balloonwall 720. For example, in the depicted embodiment the overlaid material730 is bonded to the balloon wall 720 at a bonded region 732. The bondedregion 732 fully surrounds the opening 710.

The overlaid material 730 defines a plurality of openings 734. Theopenings 734 allow fluid flowing from opening 710 to flow out onto theexterior surface of the overlaid material 730. Hence, balloon 700 is aweeping balloon.

The configuration of example weeping balloon 700 can provide a number offunctional advantages. First, the overlaid material 730 can stiffen theweeping balloon 700 in the area around the opening 710. Hence, theoverlaid material 730 can provide resistance to an enlarging of theopening 710 that may otherwise occur in response to pressurization ofthe balloon 700. Second, the overlaid material 730 can serve as aone-way valve. That is, while the overlaid material 730 allows fluidflowing from the opening 710 to pass through onto the exterior surfaceof the overlaid material 730, the overlaid material 730 will tend toresist fluid flow in the reverse direction. That is the case because, inthe depicted embodiment, there are no openings 734 that overlapping orthat are coincident with the opening 710. Therefore, if the pressureexterior to the balloon 700 is greater than the pressure interior to theballoon 700, the overlaid material 730 will be pressed against theballoon wall 720, thereby advantageously sealing the opening 710.

Referring to FIGS. 10 and 11, another example weeping balloon 800 can beconfigured to control the passage of fluid through an opening 810. Whilea single opening 810 is depicted in this portion of weeping balloon 800,it should be understood that, as described above, any number of suchopenings 810 can be included in the weeping balloon 800. In the depictedembodiment, the opening 810 is defined by the balloon wall 820. In FIG.10, the opening 810 is depicted in an unstressed state. In FIG. 11, theopening 810 is depicted in a stressed state such as would result fromfluid flowing outward from the interior of the balloon 800 through theopening 810.

In the depicted embodiment, the opening 810 is a slit that is configuredto resist tearing. Opening 810 includes a middle portion 812, a firstend 814 a, and a second end 814 b. The ends 814 a and 814 b are shaped(i.e., radiused) to advantageously mitigate stress concentrations in theballoon wall 820. Opening 810 may be included in any of the weepingballoon embodiments described herein.

Referring to FIGS. 12 and 13, a weeping balloon 900 can define one ormore openings 910 through which fluid can pass. While four openings 910are depicted on this distal face of weeping balloon 900, it should beunderstood that, as described above, any number of such openings 910 canbe included in the weeping balloon 900. FIG. 12 shows a distal end viewof the weeping balloon 900. FIG. 13 shows a cross-sectional view alongsection line A-A.

Weeping balloon 900 is designed with features that are directed tokeeping the size of openings 910 substantially consistent even withfluctuations in the fluid pressure internal to the balloon 900. Inparticular, weeping balloon 900 includes ribs 930 on the balloon wall920 in the areas of the openings 910. Both the balloon wall 920 and theribs 930 define the opening 910.

The ribs 930 supplement the stiffness of balloon wall 920 aroundopenings 910 to provide greater resistance to the deformation ofopenings 910 that might otherwise occur without the presence of the ribs930. For example, as the fluid pressure within the internal spacedefined by the weeping balloon 900 increases, the balloon wall 920 willtend to stretch. The stretching of the balloon wall 920 will tend toenlarge the openings 910. Such enlarging of the openings 910 may beundesirable in some cases. For example, as the openings 910 enlarges,the openings 910 may become too large and, in result, more fluid thandesired may be transmitted through openings 910.

To resist the enlarging of openings 910, the material stiffness aroundopenings 910 can be increased by adding the ribs 930. At other areas ofthe balloon 900, the single layer balloon wall 920 (without the ribs930) can provide a higher compliance to allow for a desired low-profilecollapsibility of balloon 900, for example. In fact, the ribs 930provide longitudinal structure for the balloon 900. Therefore, by virtueof the ribs 930, the balloon 900 will advantageously tend to collapseinto a low-profile cross shape (rather than randomly).

In some embodiments, the ribs 930 are made of the same material as theballoon wall 920. For example, in some embodiments both the balloon wall920 and the ribs 930 are made of silicone with about a 30 A durometer.In some embodiments, the ribs 930 are made of a different material thanthe balloon wall 920. For example, in some embodiments the ribs 930 aremade of PEBAX® while the balloon wall 920 is made of silicone (e.g.,about 30 A durometer). It should be understood that other combinationsof materials are also envisioned. In another non-limiting example, theballoon wall 920 is made of silicone at a first durometer (e.g., about30 A durometer) and the ribs 930 are made of silicone at a seconddurometer (e.g., about 50 A durometer). Further, in some embodiments theribs 930 are made of a hydrophilic PEBAX® such as MV1074 SA01 MED(Hydrophilic grade). In some cases, the construction of the ribs 930 caninclude one or more fibers that provide mechanical reinforcement againstdeformation of the ribs 930. All foregoing materials and constructionsmay be used in any of the other embodiments provided herein.

The ribs 930 are attached to the balloon wall 920. In some cases, theribs 930 and balloon wall 920 are made of a single unitary construct. Insome cases, the ribs 930 are molded onto the balloon wall 920 using atwo-step molding process. In some cases, an adhesive is used to bond theribs 930 to the balloon wall 920. For example, in some cases a UVcurable silicone adhesive is used to bond the ribs 930 to the balloonwall 920. Other types of adhesives can also be used.

As described above, both the ribs 930 and the balloon wall 920 definethe openings 910. In the depicted embodiment, the openings 910 are thesame size in each of the ribs 930 and the balloon wall 920. In someembodiments, the opening defined by the ribs 930 is larger than theopening defined by the balloon wall 920. In some embodiments, theopening defined by the ribs 930 is smaller than the opening defined bythe balloon wall 920. For example, in some embodiments the diameters ofthe openings defined by the ribs 930 and the balloon wall 920 differ byabout 5% to about 15%, or about 10% to about 20%, or about 15% to about25%, or about 20% to about 30%, or about 25% to about 35%, or about 30%to about 40%, or more than about 40%.

The openings 910 can be created by various techniques including, but notlimited to, cut using a scalpel, die cut, laser cut, or molded in. Insome embodiments, the openings 910 do not extend radially from a centerof the balloon 900.

While in the depicted embodiment the opening 910 is a slit, in someembodiments the opening 910 has a different shape. For example, in someembodiments the opening 910 is a slot, a circular opening, ovularopening, elliptical opening, rectangular opening, triangular opening,and the like. In some embodiments, different shapes may be used for theopenings 910 at different locations on the weeping balloon 900.

Second, the ribs 930 can help the openings 910 to function as one-wayvalves. That is, while the ribs 930 allow fluid flowing from the opening910 to pass through onto the exterior surface of the balloon wall 920and/or the ribs 930, the ribs 930 will tend to resist fluid flow in thereverse direction. For example, if the pressure exterior to the balloon900 is greater than the pressure interior to the balloon 900, the ribs930 will be pressed against the balloon wall 920 and/or ribs 930,thereby advantageously sealing the openings 910.

Referring to FIGS. 14 and 15, an example weeping balloon 1000 isdepicted in a collapsed low-profile configuration. Weeping balloon 1000is molded in the shape as depicted. That is, the weeping balloon 1000 ismolded to include a plurality of folds defined by the balloon wall 1020.The folds extend radially along generally linear paths.

Referring also to FIGS. 16 and 17, another example weeping balloon 1100is depicted in a collapsed low-profile configuration. Weeping balloon1100 is molded in the shape as depicted. That is, the weeping balloon1100 is molded to include a plurality of folds defined by the balloonwall 1120. The folds extend radially along curved paths.

Referring also to FIGS. 18 and 19, at the crotches 1024 between thefolds 1026 of the balloon wall 1020 (using weeping balloon 1000 as arepresentative example of both weeping balloons 1000 and 1100), one ormore openings 1010 can be defined by the balloon wall 1020. FIG. 18shows a cross-sectional view of a crotch between the folds of theballoon wall 1020 at the location of an opening 1010. FIG. 19 shows thesame portion of weeping balloon 1000 when the weeping balloon 1000 isinflated. It should be understood that the openings 1010 can be holes ofany shape, or slits, and any other configuration as described herein.

In the deflated configuration of FIG. 18, the opening 1010 isadvantageously sealed closed. However, in the inflated configuration ofFIG. 19, the opening 1010 is advantageously opened to a controlledextent to allow balloon 1000 to be a weeping balloon.

The thickness of the balloon wall 1020 can be increased (e.g., as shown)around the openings 1010 in some embodiments. In result, the balloonwall 1020 will be stiffer around the openings 1010 to resist enlargementof the openings 1010 while balloon 1000 is inflated.

Referring to FIGS. 20-22, a weeping balloon 1200 can define one or moreopenings 1210 through which fluid can pass. While four openings 1210 aredepicted on this distal face of weeping balloon 1200, it should beunderstood that, as described above, any number of such openings 1210can be included in the weeping balloon 1200. FIG. 20 shows a distal endview of the weeping balloon 1200. FIG. 21 shows a cross-sectional viewof a first configuration (partially inflated) along section line B-B.FIG. 22 shows a cross-sectional view of a second configuration (fullyinflated) along section line B-B.

In some embodiments, the balloon wall 1220 is molded to include one ormore localized depressions 1222 in the distal face of the weepingballoon 1200. An opening 1210 can be defined near the center, bottomregion of each depression 1222. While the weeping balloon 1200 ispartially inflated (as depicted by FIGS. 20 and 21), the openings 1210are advantageously sealed closed. However, in the fully inflatedconfiguration as shown in FIG. 22, the depressions 1222 expand outward(thereby effectively eliminating the depressions 1222) and the openings1210 are advantageously opened to a controlled extent to allow balloon1200 to be a weeping balloon.

The thickness of the balloon wall 1220 can be increased (e.g., as shown)around the openings 1210 in some embodiments. In result, the balloonwall 1220 will be stiffer around the openings 1210 to resist enlargementof the openings 1210 while balloon 1200 is fully inflated.

A number of embodiments of the weeping balloon devices for use withballoon catheter visualization devices and other medical devices,systems, and methods have been described. Nevertheless, it will beunderstood that various modifications may be made without departing fromthe spirit and scope of the subject matter described herein. Moreover,it should be understood that the features of one or more of the weepingballoon devices described herein can be combined with features from oneor more other weeping balloon devices provided herein. That is, hybriddesigns can be created by combining various features and such hybriddesigns are fully within the scope of this disclosure. Accordingly,other embodiments are within the scope of the disclosure and thefollowing claims.

What is claimed is:
 1. A weeping balloon device comprising: a cathetershaft defining a lumen; an inflatable balloon attached to the cathetershaft, the inflatable balloon comprising a balloon wall defining aninterior space in fluid communication with the lumen, the balloon walldefining a plurality of openings in fluid communication with theinterior space, wherein at least one opening of the plurality ofopenings is a slit and at least one end of the slit is formed to includea stress concentration relief shape; and at each opening of theplurality of openings, at least one additional layer of material isattached to the balloon wall.
 2. The device of claim 1, wherein thestress concentration relief shape is curved.
 3. The device of claim 2,wherein the stress concentration relief shape is a portion of a circle.4. The device of claim 2, wherein the stress concentration relief shapeis oval.
 5. The device of claim 1, further comprising a hydrophiliccoating on at least one of an exterior surface and an interior surfaceof the inflatable balloon.
 6. The device of claim 1, wherein theplurality of openings are disposed only on a distal face of theinflatable balloon.
 7. The device of claim 1, wherein each additionallayer of material defines an additional opening that is concentric witha corresponding opening of the plurality of openings defined by theballoon wall.
 8. The device of claim 1, wherein at least one of theadditional layers of material does not define any openings.
 9. Thedevice of claim 8, wherein an open region between the at least oneadditional layer of material and the balloon wall provides a passagewayin fluid communication with the opening through the balloon wall that isat the at least one additional layer of material.
 10. The device ofclaim 1, wherein at least one of the additional layers of materialdefines a plurality of additional openings that are in fluidcommunication with the opening through the balloon wall that is at theat least one additional layer of material.
 11. The device of claim 10,wherein the plurality of additional openings are smaller than theopening through the balloon wall that is at the at least one additionallayer of material.
 12. The device of claim 1, wherein the balloon wallis made of a first material and the additional layer of material is madeof a second material, wherein the second material has a higher durometerthan the first material.
 13. A weeping balloon device comprising: acatheter shaft defining a lumen; an inflatable balloon attached to thecatheter shaft, the inflatable balloon comprising a balloon walldefining an interior space in fluid communication with the lumen, theballoon wall defining a plurality of openings in fluid communicationwith the interior space, wherein at least one opening of the pluralityof openings is a slit and both ends of the slit are formed to include acurved stress concentration relief shape; and at each opening of theplurality of openings, at least one additional layer of material isattached to the balloon wall.
 14. The device of claim 13, wherein thestress concentration relief shape is a portion of a circle.
 15. Thedevice of claim 13, wherein the stress concentration relief shape isoval.
 16. The device of claim 13, wherein the plurality of openings aredisposed only on a distal face of the inflatable balloon.
 17. The deviceof claim 13, wherein each additional layer of material defines anadditional opening that is concentric with a corresponding opening ofthe plurality of openings defined by the balloon wall.
 18. The device ofclaim 13, wherein at least one of the additional layers of material doesnot define any openings, wherein an open region between the at least oneadditional layer of material and the balloon wall provides a passagewayin fluid communication with the opening through the balloon wall that isat the at least one additional layer of material.
 19. The device ofclaim 1, wherein the balloon wall is made of a first material and theadditional layer of material is made of a second material, wherein thesecond material has a higher durometer than the first material.
 20. Aweeping balloon device comprising: a catheter shaft defining a lumen; aninflatable balloon attached to the catheter shaft, the inflatableballoon comprising a balloon wall defining an interior space in fluidcommunication with the lumen, the balloon wall defining a plurality ofopenings in fluid communication with the interior space, wherein atleast one opening of the plurality of openings is a slit and both endsof the slit are formed to include a rounded stress concentration reliefshape; and at each opening of the plurality of openings, at least oneadditional layer of material is attached to an exterior of the balloonwall, each additional layer of material defining an additional openingthat is concentric with a corresponding opening of the plurality ofopenings defined by the balloon wall.